You will finde all the necessary information on the Web site of the ARRL so please have a look in the "Licensing, Education & Traning" section.
Special the subsection "Getting Licensed" will be interesting for you:
Notice the validation of the question pools:
- Technician (Element 2) until 30th Juni 2026
- General (Element 3) until 30th Juni 2023
- Amateur Extra (Element 4) until 30th Juni 2024
For your exam preparation there two printed books or ebooks (Kindle) available from the ARRL for each license class:
- License Manual 5rd Edition (Technician) | Tech Q&A 8th Edition
- General Class License Manual 9th Edition | General Q&A 6th Edition
- Extra Class License Manual 12th Edition | Extra Q&A 5rd Edition
Please use the latest valid issues only. You can order the printed issues form the ARRL online store and the ebooks via the Kindle online store from Amazone.
There are different possibilities of traning for your exams:
Online training at the ARRL: http://arrlexamreview.appspot.com/
A nice training Web site is HamStudy.org: https://hamstudy.org/
Apps for iOS and Android mobile devices are also available from hamstudy.org.
If you are using other apps check if they are using the latest question pool.